1. Field of the Invention
An embodiment of the present invention relates to a computer system, and more particularly, to a method and an apparatus for improving user convenience and security by selectively performing user authentication when rebooting.
2. Description of the Related Art
Computer systems provide a variety of functions to many segments of today's modern society. A computer system may be a desktop or portable computer that consists of a system unit comprising a processor, associated volatile and nonvolatile memory, a display monitor, a keyboard, one or more diskette drives, fixed disk storage, and an optional printer. As computer systems are widely used in offices as well as at home, security of computer systems has become an important issue. Primary security of data inside a computer system relies on a basic input/output system (BIOS) password and an operating system (OS) password, which are prompted for when a computer system is booted.
Booting is a series of procedures required before a computer becomes operable. When a power switch of a computer is turned on for booting, a basic program called a ROM BIOS operates first. The program is recorded in a nonvolatile memory called a read only memory (ROM), which cannot be erased or lost even when the power is turned off. In the case of a booting operation of an IBM PC compatible computer, an inspection called a power on self test (POST) is performed first. Although the POST is performed in slightly different ways according to the contents of the ROM BIOS, an error message with an alarm is displayed on a monitor and booting stops if RAM used as main memory, a keyboard, or a hard disc are found to have any problems.
When the POST is completed, the operating system (OS) of a computer system is read and made resident in memory. A user refers to the ROM BIOS in order to obtain information about which drive the operating system (OS) is to be read from. The above-described booting procedure is usually referred to as cold booting. On the other hand, warm booting is a procedure in which the POST is not performed during booting. The computer system finishes the booting operation successfully before the user may perform a desired task.
Rebooting is a procedure in which a booting operation is performed to start the operating system (OS) again if an error occurs when, for example, a computer is running or information about the settings of a computer system is changed and the operating system should be run again or volatile information throughout the entire system is removed. Rebooting usually takes the form of warm rebooting, in which the POST is not performed thereby shortening the booting procedure.
The BIOS that performs booting is a kind of program run by a microprocessor when a computer system is turned on. The BIOS also manages data flow between peripheral devices such as hard disks, video adaptors, keyboards or mice etc. and the operating system (OS). The BIOS is stored in ROM. Recently, the BIOS has also been stored in changeable ROMs such as erasable programmable read only memories (EPROMs) or electrically erasable programmable read only memories (EEPROMs). A password can be set during BIOS booting so that when another person has access to the computer system, the computer system is prevented from being operated and power can be cut off.
The BIOS reads setting information of the computer system when starting. The setting information is usually changeable and maintainable. Thus, the setting information needs to be stored in nonvolatile and writable memory. In a typical computer system, the setting information of the BIOS is stored in a complementary metal oxide semiconductor (CMOS). Most computer microchips use CMOS type transistors. When the BIOS performs booting using the CMOS, necessary information can be changed.
The setting information related to the execution of the BIOS stored in the nonvolatile memory such as a CMOS includes a BIOS password. With the BIOS password, when user authentication is performed at an initial stage of booting using the BIOS and an error occurs in checking a password, the power of the computer system is cut off to prevent other people from accessing the computer system. The OS starts operating after the BIOS starts running, and user certification or authentication such as the entry of a password can be performed again when the operating system (OS) is first accessed.
The BIOS password and an OS password, when password protection is activated, are required to be input every time when booting. Since many users find this to be inconvenient, they often avoid using a password altogether. In particular, when installing and upgrading software, rebooting frequently occurs so that the entire system can be effectively executed, which in turn requires the frequent entry of a password. This may cause inconvenience to a verified user. In the prior art, a method for deactivating a password requirement utilizing a wireless signal so that the entry of a password can be selectively performed during booting is disclosed in U.S. Pat. No. 6,370,650. However, the wireless signal is applied to all types of booting (cold and warm), and the entry of a password is not deactivated only during rebooting. As a result, it is difficult to maintain security due to the drawback of the wireless signal. In addition, a method of managing a password related to network connection has been proposed but cannot prevent operation of the computer system.
Accordingly, a method by which rebooting can be performed without user authentication is desirable.